This invention relates to RFID (Radio Frequency Identification) technologies used in conjunction with EPC (Electronic Product Code) information applications. Electronic Product Codes (EPC) is a family of coding schemes for RFID (Radio Frequency IDentification) tags. The EPC is designed to meet the needs of various industries, while guaranteeing the uniqueness for all EPC-compliant tags. All EPC numbers contain a header identifying the encoding scheme that has been used. This in turn dictates the length, type and structure of the EPC. EPC coding schemes typically contain a serial number which can be used to uniquely identify a single object.
The RFID and EPC technologies provide the basis for traceability applications that gather data about tagged items as they move through a supply chain. Some examples of items include raw materials, parts, finished goods and Reusable Transport Items (RTI's) used to transport items around the world. The collected data can be analyzed to better understand and optimize the supply chain through techniques, such as track and trace, and through metrics, such as usage, dwell time, down time, Mean Time Between Failure and inventory.
Track and trace and analytic applications that span links in the supply chain make use of the chain of custody or pedigree of tagged items. The chain of custody or pedigree can be determined through a Discovery Service that maintains a list of custodians for an item. Track and trace techniques and supply chain analytics are of interest to those directly involved in the commercial supply chain—manufacturers, distributors, transportation service providers and retailers. In many cases, authorities and governing bodies can also find value in and require access to this information, for example: port authorities, customs and excise agencies and import/export and border control.
The primary means of identification for tagged items is the EPC, which can be encoded on an RFID tag or a bar code or using some other identification technology. Various agencies, authorities and industries may require use of additional identifiers, for example, the World Customs Organization has defined the Unique Consignment Reference (UCR), which “Like an electronic staple designed for e-commerce, a UCR binds information together all the bits of date about a trade transaction, from initial order and consignment of goods by a supplier, to the movement of those goods and arrival at the border, through to their final delivery to the importer” (WCO Unique Consignment Reference (UCR), June 2004) or “Freight containers—Coding, identification and marking” (ISO 6346:1995), which requires a defined container ID to be visible on the outside of a container.
In the case of containers transporting goods across international boundaries, RFID readers or similar devices will read the EPC code, but customs authorities will expect to use UCR and a customs agent on the ground in a port may have no access to electronic readers or information systems and may only be able to reference the container ID that is marked on the outside of the container. This is one example of a common situation that occurs where different organizations, authorities and businesses cooperate to conduct business while using distinct identification methods.
Furthermore, reusable transport items (RTIs) including pallets, totes and containers are used throughout the supply chain to aggregate items for transportation. Using RFID technologies, RTIs can be tagged in the same way as the items they contain. Just like for any other items, this allows the owners and users of the RTIs to gather data about the movement and use of the RTIs, which can be analyzed to better understand and optimize use of RTIs.
However, unlike finished goods, which typically traverse a supply chain once from a manufacturer to an end user, RTIs are repeatedly used and may circulate around the supply chain for several years. While RTIs can be tagged and identified in the same way as other items, this is not sufficient information to identify a specific trip that the RTI makes through a supply chain because the same EPC will be used every trip. Using EPC alone, the discovery service cannot distinguish trips, so the chain of custody for an RTI would start with its first use and continue through all trips to the latest. In the life of an RTI, this might include being used by competitive businesses. Thus, there is a need for improved techniques to provide correct track and trace information and to maintain confidentiality for RTIs.